Toxic air pollutants like mercury from coal- and oil-fired power plants have been shown to cause neurological damage, including lower IQ, in children exposed in the womb and during early development. The standards also address emissions of other toxic metals linked with cancer such as arsenic, chromium and nickel. Mercury and many of the other toxic pollutants also damage the environment and pollute our nation's lakes, streams, and fish. In addition, cutting these toxic pollutants also reduces fine particle pollution, which causes premature death, heart disease, workdays lost to illness and asthma.
Power plants are the largest remaining source of several toxic air pollutants – responsible for half of mercury and more than half of acid gas emissions in the United States. In the power sector alone, coal-fired power plants are responsible for 99 percent of mercury emissions.
The proposed standards also ensure that public health and economic benefits far outweigh costs of implementation. EPA estimates that for every dollar spent to reduce pollution from power plants, the American public and American businesses will see up to $13 in health and economic benefits. The total health and economic benefits of this standard are estimated to be as much as $140 billion annually.
From the EPA Press Release